Kernikterus: Jaundice of the Nuclear Masses of the Brain *

In 1903 Schmorl4 defined Kernikterus as jaundice of the nuclear masses of the brain. It includes usually the caudate, lenticulate, subthalamic and dentate nuclei, the thalami, mammillary bodies, Ammon's horns, the nuclei of the cranial nerves, the olives, parts of the cerebellar cortex and the anterior and posterior horns of the spinal cord. Kernikterus is almost always associated with icterus gravis neonatorum, in which condition, however, it is a rare concomitant finding. Schmorl reported but six instances of jaundice of the nuclear masses of the brain in 130 autopsies of infants with icterus gravis. The theories relating to the etiology of icterus gravis have been summarized by Zimmerman and Yannet6, who emphasized the concept that it is frequently a manifestation of generalized infection, ofttimes a septicemia. These workers feel that sepsis is an important etiologic factor in many cases and that failure to perform adequate bacteriological studies of the blood in icterus gravis has obscured the role of infection. Other theories offered in explanation of Kernikterus were summarized by Benekel as follows: (1) Peculiar attraction of bile pigment for ganglion cells, resulting in deposition of pigment and subsequent necrosis of these cells. (2) Primary damage of ganglion cells by bile salts with secondary cellular pigmentation. (3) Primary damage of ganglion cells by ischemia or trauma and subsequent deposition of pigment. Orth3 reported an instance of Kernikterus which, in his opinion, was preceded by necrosis of the ganglion cells. Schmorl believed that necrosis of the nerve cells was the result of vascular damage caused by a toxin or thrombus, and that this was followed by deposition of bile in the injured cells. Other suggestions which have been offered to account for injury to the nerve cells are: infectious agents,